Index Geophysics

Time-resolved characterization of primary particle emissions and secondary
particle formation from a modern gasoline passenger car

Changes in vehicle emission reduction technologies significantly affect traffic-related emissions in urban areas. In many densely populated areas the amount of traffic is increasing, keeping the emission level high or even increasing. To understand the health effects of traffic-related emissions, both primary (direct) particulate emission and secondary particle formation (from gaseous precursors in the exhaust emissions) need to be characterized. In this study, we used a comprehensive set of measurements to characterize both primary and secondary particulate emissions of a Euro 5 level gasoline passenger car. Our aerosol particle study covers the whole process chain in emission formation, from the tailpipe to the atmosphere, and also takes into account differences in driving patterns. We observed that, in mass terms, the amount of secondary particles was 13 times higher than the amount of primary particles. The formation, composition, number and mass of secondary particles was significantly affected by driving patterns and engine conditions. The highest gaseous and particulate emissions were observed at the beginning of the test cycle when the performance of the engine and the catalyst was below optimal. The key parameter for secondary particle formation was the amount of gaseous hydrocarbons in primary emissions; however, also the primary particle population had an influence.

Karjalainen, Panu

Timonen, Hilkka

Saukko, Erkka

Kuuluvainen, Heino

Saarikoski, Sanna

Aakko-Saksa, Päivi

Murtonen, Timo

Bloss, Matthew

Maso, Miikka

Simonen, Pauli

Ahlberg, Erik

Svenningsson, Birgitta

Brune, William Henry

Hillamo, Risto

Keskinen, Jorma

Rönkkö, Topi

2018-09-10

Text

application/pdf

10.5194/acp-16-8559-2016

https://acp.copernicus.org/articles/16/8559/2016/

eISSN: 1680-7324

eng